#include <stdio.h>

void interchange(int * u, int * v);

int main(void) {
    int x = 5, y = 10;
    
    printf("Originally x = %d and y = %d.\n", x, y);

//    int temp = x;
//    x = y;
//    y = temp;
    interchange(&x, &y);

    printf("Now x = %d and y = %d.\n", x, y);

    return 0;
}

void interchange(int * u, int * v) {
    int temp;
    temp = *u;
    *u = *v;
    *v = temp;
}
    
